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The Journal of Organic Chemistry Aug 2022Bambusurils are macrocyclic molecules that are known for their high binding affinity and selectivity toward anions. Here, we present the preparation of two bambusurils...
Bambusurils are macrocyclic molecules that are known for their high binding affinity and selectivity toward anions. Here, we present the preparation of two bambusurils bearing fluorinated substituents and one carboxylic function. These monofunctionalized bambusurils were conjugated with crown ether and cholesterol units. The resulting conjugates were successfully tested in liquid-liquid extraction of inorganic salts and chloride/bicarbonate transport across lipid bilayers.
Topics: Anions; Chlorides; Crown Ethers; Lipid Bilayers
PubMed: 35862261
DOI: 10.1021/acs.joc.2c00870 -
Journal of Chromatography. A Sep 2023Novel grafted anion exchangers with covalently bonded hyperbranched functional layers were prepared and evaluated for the separation of monovalent standard inorganic...
Novel grafted anion exchangers with covalently bonded hyperbranched functional layers were prepared and evaluated for the separation of monovalent standard inorganic anions and oxyhalides. Preparation of base coating included grafting highly polar N-vinylformamide to the ethylvinylbenzene-divinylbenzene (EVB-DVB) substrate surface in highly polar solvent (methanol) with subsequent hydrolysis of grafted amide polymer in basic media, which resulted in preparation of polymer chains with multiple primary amino groups. Those amino groups were used as attachment points for forming hyperbranched anion-exchange layers using 1,4-butanediol diglycidyl ether and primary mono- or diamine (methylamine or 1,3-diaminopropane, respectively). The effects of hyperbranching reaction cycles number on selectivity were evaluated which revealed that selectivity and capacity can be controlled independently for the covalently bonded stationary phases in contrast to electrostatically bonded phases. It was demonstrated that unlike for electrostatically bonded phases, the intentional increase of crosslink by using primary diamine instead of primary monoamine doesn't cause the shift of selectivity coefficients. It was also shown that crosslink distribution throughout the hyperbranched layer is an important factor determining selectivity of hyperbranched anion exchangers.
Topics: Chromatography, Ion Exchange; Anions; Amines
PubMed: 37523909
DOI: 10.1016/j.chroma.2023.464218 -
Nature Communications Oct 2022Transmembrane ion transport is a key process in living cells. Active transport of ions is carried out by various ion transporters including microbial rhodopsins (MRs)....
Transmembrane ion transport is a key process in living cells. Active transport of ions is carried out by various ion transporters including microbial rhodopsins (MRs). MRs perform diverse functions such as active and passive ion transport, photo-sensing, and others. In particular, MRs can pump various monovalent ions like Na, K, Cl, I, NO. The only characterized MR proposed to pump sulfate in addition to halides belongs to the cyanobacterium Synechocystis sp. PCC 7509 and is named Synechocystis halorhodopsin (SyHR). The structural study of SyHR may help to understand what makes an MR pump divalent ions. Here we present the crystal structure of SyHR in the ground state, the structure of its sulfate-bound form as well as two photoreaction intermediates, the K and O states. These data reveal the molecular origin of the unique properties of the protein (exceptionally strong chloride binding and proposed pumping of divalent anions) and sheds light on the mechanism of anion release and uptake in cyanobacterial halorhodopsins. The unique properties of SyHR highlight its potential as an optogenetics tool and may help engineer different types of anion pumps with applications in optogenetics.
Topics: Anion Transport Proteins; Halorhodopsins; Rhodopsins, Microbial; Synechocystis; Anions; Sulfates
PubMed: 36309497
DOI: 10.1038/s41467-022-34019-9 -
Journal of the American Chemical Society May 2022Inspired by the success of its related sigma-hole congener halogen bonding (XB), chalcogen bonding (ChB) is emerging as a powerful noncovalent interaction with a...
Inspired by the success of its related sigma-hole congener halogen bonding (XB), chalcogen bonding (ChB) is emerging as a powerful noncovalent interaction with a plethora of applications in supramolecular chemistry and beyond. Despite its increasing importance, the judicious modulation of ChB donor strength remains a formidable challenge. Herein, we present, for the first time, the reversible and large-scale modulation of ChB potency by electrochemical redox control. This is exemplified by both the switching-ON of anion recognition via ChB oxidative activation of a novel bis(ferrocenyltellurotriazole) anion host and switching-OFF reductive ChB deactivation of anion binding potency with a telluroviologen receptor. The direct linking of the redox-active center and ChB receptor donor sites enables strong coupling, which is reflected by up to a remarkable 3 orders of magnitude modulation of anion binding strength. This is demonstrated through large voltammetric perturbations of the respective receptor ferrocene and viologen redox couples, enabling, for the first time, ChB-mediated electrochemical anion sensing. The sensors not only display significant anion-binding-induced electrochemical responses in competitive aqueous-organic solvent systems but can compete with, or even outperform similar, highly potent XB and HB sensors. These observations serve to highlight a unique (redox) tunability of ChB and pave the way for further exploration of the reversible (redox) modulation of ChB in a wide range of applications, including anion sensors as well as molecular switches and machines.
Topics: Anions; Chalcogens; Halogens; Oxidation-Reduction; Solvents
PubMed: 35522996
DOI: 10.1021/jacs.2c02924 -
Journal of the American Chemical Society Sep 2022A new type of cage inherent chirality was accessed by hierarchical desymmetrization of a -symmetric prismlike cage motif. The dissymmetric cage precursor bearing two...
A new type of cage inherent chirality was accessed by hierarchical desymmetrization of a -symmetric prismlike cage motif. The dissymmetric cage precursor bearing two different phloroglucinol caps was first synthesized. The subsequent progressive substitutions on the three triazine arms by different nucleophiles furnished the desired -symmetric inherently chiral cages and with rich structural diversity. Resolution of the racemic cages was achieved by chiral chromatography, and the enantiopure cages were readily obtained on the gram scale. Convenient post-synthetic transformations of the chiral cages with retention of enantiomeric purity were also realized. The absolute configuration was determined by X-ray crystallography, and a chirality descriptor was provided to define the cage chirality. With the inherently chiral array of the electron-deficient triazine surfaces constituting three individual chiral V-shaped π cavities, regio- and enantioselective anion-π binding was probed for the first time with minimum interference of other interactions. As exemplified with chiral phosphate anions (CPAs), it was found that cage (-)- preferably binds ()-CPA in the most electron-deficient cavity through synergistic anion-π interactions with considerable chiral selectivity.
Topics: Anions; Phloroglucinol; Phosphates; Stereoisomerism; Triazines
PubMed: 36070570
DOI: 10.1021/jacs.2c08591 -
Chemphyschem : a European Journal of... Jan 2023Ever since the inception of anion-π interactions, their nature and functional relevance have intrigued researchers. We address the twin challenge of elucidation of the...
Ever since the inception of anion-π interactions, their nature and functional relevance have intrigued researchers. We address the twin challenge of elucidation of the role of extended conjugation and design of all-carbon neutral anion receptors by computations on the anion-π complexes of the halide ions with graphynes. Leveraging on the extended π-conjugation effects, we unfurl the functional relevance of graphynes as anion receptors using descriptors such as electrostatic potential, quadrupole moments, molecular polarizabilities and binding energies. Further, employing natural energy decomposition analysis, we assert that anion-π interactions are not merely dominated by electrostatic interactions. The polarization components do indeed play a crucial role in governing the binding of the anions to the graphynes.
Topics: Anions; Thermodynamics
PubMed: 36068988
DOI: 10.1002/cphc.202200548 -
Angewandte Chemie (International Ed. in... Jun 2023Aziridines are highly valued synthetic targets in organic and medicinal chemistry. The organocatalytic synthesis of such structures with broad substrate scope and good...
Aziridines are highly valued synthetic targets in organic and medicinal chemistry. The organocatalytic synthesis of such structures with broad substrate scope and good diastereoselectivity, however, is rare. Herein, we report a broadly applicable and diastereoselective synthetic method for the synthesis of trans-aziridines from imines and benzylic or alkyl halides utilizing sulfenate anions (PhSO ) as the catalyst. Substrates bearing heterocyclic aromatic groups, alkyl, and electron-rich and electron-poor aryl groups were shown to be compatible with this method (33 examples), giving good yields and high diastereoselectivities (trans : cis >20 : 1). Further functionalization of aziridines containing cyclopropyl or cyclobutyl groups was achieved through ring-opening reactions, with a cyclobutyl-substituted norephedrine derivative obtained through a four-step synthesis. We offer a mechanistic proposal involving reversible addition of the deprotonated benzyl sulfoxide to the imine to explain the high trans-diastereoselectivity.
Topics: Aziridines; Anions; Imines; Catalysis; Stereoisomerism
PubMed: 37068049
DOI: 10.1002/anie.202303069 -
Small (Weinheim An Der Bergstrasse,... Apr 2023The chemical generation of singlet oxygen ( O ) by the MoO -catalyzed disproportionation of hydrogen peroxide (H O ) has been widely applied in numerous catalytic...
The chemical generation of singlet oxygen ( O ) by the MoO -catalyzed disproportionation of hydrogen peroxide (H O ) has been widely applied in numerous catalytic processes; however, such molybdate ions cannot be administered for redox-based cancer therapeutics. This work reports the albumin-mediated biomimetic synthesis of highly active molybdenum sulfide (denoted MoB) nanocatalysts that mediate the simultaneous generation of O and superoxide anion (O ) from H O , which is relatively abundant in malignant tumors. The MoB-catalyzed reactive oxygen species (ROS) are able to activate the ferroptosis pathway and cause lipid peroxidation for efficient cancer therapy. Furthermore, for the first time, the catalytic activity of MoB is visualized in situ. Moreover, a catalytic imaging modality based on MoB is developed for specific imaging of inflammation diseases without background interference. Therefore, this study presents a biomimetic strategy toward Mo-based nanocatalysts for ROS-facilitated tumor ferroptosis and catalytic imaging.
Topics: Humans; Biomimetics; Catalysis; Cell Line, Tumor; Ferroptosis; Hydrogen Peroxide; Neoplasms; Reactive Oxygen Species; Anions
PubMed: 36683226
DOI: 10.1002/smll.202207544 -
The Analyst Jul 2022Compared with the well-studied cations, the development of methods for anion detection is relatively slow due to the anion characteristics such as a complex geometry,...
Compared with the well-studied cations, the development of methods for anion detection is relatively slow due to the anion characteristics such as a complex geometry, strong hydration and a low charge density. Herein, a colorimetric and ratiometric fluorescent anion sensing platform based on trihexyltetradecylphosphonium chloride ([THTP][Cl]) was developed for the first time. Such nanosensors exhibited a pH response of 5-7 as well as a high selectivity to perchlorate. The selectivity behavior followed the Hofmeister series in which lipophilic anions were more readily co-extracted. To deviate from the Hofmeister series, anion ionophores should be introduced for selective complexation of the target anions. As a proof of concept, the organomercury compounds ETH9033 and ETH9009 were employed as model ionophores. The obtained nitrate- and chloride-selective [THTP][Cl]-based nanosensors demonstrated prominent colorimetric and spectroscopic transformations specifically induced by the anion species. The fluorescence (/) and absorbance (/) intensities the logarithm values of anion concentrations proved a high selectivity towards the major anion. The excellent performance such as high selectivity, good sensitivity and fast response times enabled the accurate determination of nitrate in mineral water. More importantly, through simply altering the ionophores, a pool of [THTP][Cl]-based anion-selective nano-optodes for extended targets could be achieved. The nanosensor shows great potential for anion determination in the environmental and biomedical fields.
Topics: Anions; Chlorides; Ionophores; Nitrates; Organophosphorus Compounds
PubMed: 35708052
DOI: 10.1039/d2an00735e -
Molecules (Basel, Switzerland) Sep 2022Besides their extremely useful properties as solvent, ionic liquids (ILs) are now considered to be highly instructive tools for enhancing the rates of chemical... (Review)
Review
Besides their extremely useful properties as solvent, ionic liquids (ILs) are now considered to be highly instructive tools for enhancing the rates of chemical reactions. The ionic nature of the IL anion and cation seems to be the origin of this fascinating function of ILs as organocatalyst/promoter through their strong Coulombic forces on other ionic species in the reaction and also through the formation of hydrogen bonds with various functional groups in substrates. It is now possible to tailor-make ILs for specific purposes as solvent/promoters in a variety of situations by carefully monitoring these interactions. Despite the enormous potentiality, it seems that the application of ILs as organocatalysts/promoters for chemical reactions have not been fully achieved so far. Herein, we review recent developments of ILs for promoting the nucleophilic reactions, focusing on fluorination. Various aspects of the processes, such as organocatalytic capability, reaction mechanisms and salt effects, are discussed.
Topics: Anions; Halogenation; Hydrogen Bonding; Ionic Liquids; Solvents
PubMed: 36080470
DOI: 10.3390/molecules27175702